(a) Field of the Invention
The present invention relates to a battery module. More particularly, the present invention relates to a rechargeable battery module for improving an assembling configuration of unit batteries to reduce resistance.
(b) Description of the Related Art
A rechargeable battery is capable of being charged and discharged, while a primary battery may not be charged.
A low capacity rechargeable battery formed by one battery cell formed in a pack is used for small portable electronic devices such as a mobile phone, a laptop computer, and a camcorder, and a large capacity battery is used for power sources for driving a motor such as for a hybrid vehicle.
The rechargeable battery is manufactured in various shapes, and typical shapes are a cylinder and a rectangle. In the rechargeable battery, a separator, that is an insulator, is provided between an anode and a cathode. The rechargeable battery also includes an electrode group which is formed by winding electrodes in a spiral shape which are positioned in a case. A cap assembly having an outer terminal is combined to the case containing the electrode.
A high power rechargeable battery using a non-aqueous electrolyte of high energy density has been recently developed. A plurality of these rechargeable batteries can be coupled in series to form a large capacity battery module so that the high power rechargeable battery may be used for a device requiring high power (e.g., a motor in an electric vehicle).
Generally, one battery module includes a plurality of rechargeable batteries (hereinafter referred to as “unit batteries”) coupled in series, and the rechargeable battery is formed in a cylindrical or rectangular shape.
To form the battery module by coupling the respective unit batteries in series, anode and cathode terminals protruded from the cap assembly of the unit battery are arranged to connect to cathode and anode terminals of adjacent unit batteries, respectively. In addition, a nut is provided to connect an anode terminal, formed as a screw, to a cathode terminal of an adjacent unit battery.
That is, respective electrode terminals have male threads and nuts that fix the terminals to the cap assembly. A connection part for electrically coupling the anode terminal of a unit battery and the cathode terminal of an adjacent unit battery is combined with the nut, and another nut is combined as a connection part to interconnect the terminals.
However, in the conventional configuration, it takes quite a long time to mount the connection part, and a manufacturing process is complicated. In addition, since the nut is used as a medium to connect the connection part to the nut, contact resistance may occur at a connected part.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.